Hydraulic jack



Feb- 12, 1952 F. M. SIEDENBURG HYDRAULIC JACK 2 SHEETSSHEET 1 Filed Aug.18, 1947 INVENTOR.

Patented Feb. 12, 1952 UNITED STATES PATENT OFFICE This inventionrelates to an improved bydraulic jack and one of its objects is toprovide a jack with a reservoir of oil or pressure fluid hav-- ing aflexible and collapsing wall and provided with valve controlledcommunication with the pressure'fluid charging chamber of the hydraulicpump or pressure generator, so that only the pressure liquid will flowto the pressure gen erator and all air will be permanently excluded-.-Another object of the invention is to provide the hydraulic jack with amanually operated is ton, a rocker for operating the piston, and a leverhaving adjustable connection with the rocker, so that the piston may beoperated; with the lever in various angular relations to the rocker.

A further object of theinvention is to provide an improved valve systemfor controlling the pressure and the return flow of the pressure fluid,so that a closed hydraulic circulation may be maintained;

,For further comprehension of the invention, and of the objects andadvantages thereof, reference will be had to the following descriptionand accompanying drawings, and to the appended claims in which thevarious novel features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

Fig. 1 is a side elevation of the improved hydraulic jack, constructedin accordance with the present invention.

Fig. 2 is a similar view, showing the opposite side.

Fig. 3 is a. view looking from the right side of Fig. 1.

'Fig. 4 is a view looking down on Fig. 1.

Fig. 5 is a view looking up on Fig. l.

' Fig. 6 is an enlarged vertical sectional view, taken-on line't-Bof'Fig. 4, looking in the direction of the arrows.

Fig. 7 is an enlarged fragmentary vertical sectional view, taken on line'l-l of Fig. 4, looking in the direction of the arrows.

Fig. 8 is a horizontal sectional view, taken on line 8-8 of Fig. 6,looking in the direction of the arrows.

The hydraulic jack, according to the present invention, includes anouter protective casing l having an end wall II at one end and an iwhich is connected by matching screw threads IE to a block II, alsoenclosed by the casing Ill.

In the cylinder l a pressure ram i8 is slidably mounted. The innerend ofthis ram, which is cylindrical, 'is equipped with a sealing or packingring l9, which is secured thereto by means of a central screw 20,against a washer 2|. The other end of the ram l8 extends slidablythrough the cylinder [5, and is sealed by means of a gland ring 22 and apacking disc or washer 23. The outer end of the ram I8 is formed withscrew threads 24, so that it may be coupled to any ex ternal device.

"I he block l! is formed with a pressure fluid charging passage 25,which establishes communication between a pump cylinder 26 and thepressure chamber 2'! of the ram cylinder E5. The

end wall 12 at the other end thereof. This caspassage 25 is controlledby a ball check valve In the pump cylinder 26 a piston 25 operates, thispiston being connected to a piston rod 30 by means of a screw 3i. Theouter end of the piston rod 30 is provided with a lateral sideopeningslot 32, which receives a pin 33 of a rocker plate fimwhich ispivoted at 35 to a bolt 35, which is coupled by the screw threads 3! tothe block ll, through the outer casing ill. The piston rod 30 where itextends from the pump cylinder 26 is sealed by a gland nut 59.

The rocker plate 34 is rocked by means of a lever 38, which is pivotedby a pin 39 to the rocker plate between the bolt 36 and the piston rod30. The lever 38 has a bifurcated inner end 45 which straddles therocker plate for this pur-- pose.

Enclosed by the outer casing 10 there is a flexible reservoir tube 4|;of oil resistant rubber or similar pliant and resilient material. Oneend oi this flexible reservoir tube is tightly fitted in a groove '42formed in an end block 43, and the opposite-end is tightly fitted on anend plug 44. The end block 43 is provided with an axial passage 45, andthe upper end of this passage is closedby a screw threaded filler plug45, which can be operated through the end wall H of the casing H), whichhas an opening ii for this purpose.

The end block 43 is also provided with a lateral The pump cylinder 28communicates with a passage 54, which extends through the block I! toits exterior, so that drainage and cleaning operations may be completed,and also communicates with the passage 41, and a ball check valve 55 isarranged in the pump chamber 26 to control the passage 54, and a plug 56is threaded into the outer end of the passage 54 to keep the samenormally sealed.

When the ram l8 reaches a safe limit of travel, it is desirable that itbe held within the cylinder 15, and for this purpose the pressure liquidfrom the cylinder is caused to shunt through a by-pass 51, which extendsthrough the cylinder and through the end plug 44 to establishcommunication between the interior of the flexible reservoir tube 4! andthe pressure chamber 2'! of the cylinder 15.

It is evident that when the rocker plate 34 is rocked by means of thelever 38, the piston rod will be reciprocated to generate pressure inthe pump cylinder 26, and pressure fluid will be forced into thepressure chamber 21 of the cylinder 15, to force the ram IS a distancecontrolled by the amount of pressure fluid admitted to the chamber 27 ofthe cylinder 15 at each pressure stroke of the lever 38.

When the piston rod 39 is moved outwardly pressure fluid will be drawninto the pump cylinder 26, and when the piston rod 30 is forced inwardlythe pressure fluid will be prevented from leaving this cylinder by theaction of the ball check valve 55, and will be forced into the mainpressure chamber 21. The outer end of the lever is equipped with ahandle 38 so that it can be operated to better advantage.

Due to the fact that a closed hydraulic circuit is established for thecirculation of the pressure fluid, from the flexible and collapsiblereservoir 41 to the pressure chamber 21, and from this pressure chamberback to the flexible reservoir tube, no air is permitted to enter thesystem. If the supply of pressure fluid in the flexible and resilientreservoir tube 4| drops too much, then the wall of this tube orreservoir will yield inwardly, thereby preventing any reduction of theinternal pressure of the tube or reservoir, and also preventing backpressure on the pressure fluid.

The rocker plate 34 is provided with open edge recesses 34, on its outerconvex surface which are engaged by the pin 40, which extends throughthe bifurcated inner end 40 of the lever, and which provides means foradjusting the angular position of the lever on the rocker plate.

While I have illustrated and described the preferred embodiments of myinvention, it is to be understood that I do not limit myself to theprecise constructions herein disclosed and the right is reserved to allchanges and modifications coming within the scope of the invention asdefined in the appended claims,

Having thus described my invention, what I claim as new, and desire tosecure by United States Letters Patent is:

1. A hydraulic jack having a hollow cylinder closed at its top end by ablock and provided with a slidable ram extendable from the bottom cf thecylinder, a flexible reservoir connected with the interior of thecylinder through valved passages formed in the block, a pump cylinderformed in the block between the valved passages and in communicationwith said passages, a piston slidably disposed in said pump cylinder, apiston rod connected to said piston within said pump cylinder and havingone end extended from the side of the block, a bolt extended from theside of the block above the extended end of said piston rod andvertically aligned therewith, a pair of spaced semi-circular rockerplates extended along the opposite sides of said bolt and the extendedend of said piston rod and pivotally attached to each with their roundedsides extended away from the side of the block, a lever extending fromsaid rocker plates, said lever being pivotally connected to said platesat a point concentric with the rounded sides of said plates, and meansreleasably retaining said lever in an inoperative position along theside of the hollow cylinder or in an operative position extendedlaterally of the block.

2. A hydraulic jack having a hollow cylinder closed at its top end by ablock and provided with a slidable ram extendable from the bottom of thecylinder upon flow of fluid under pressure through valved passagesformed in the block, a pump cylinder formed in the block between thevalved passages and in communication with said passages, a pistonslidably disposed in said pump cylinder, a piston rod connected to saidp;ston within said pump cylinder and having one end extended from theside of the block, a bolt extended from the side of the block above theextended end of said piston rod and vertically aligned therewith, a pairof spaced semi-circular rocker plates extended along the opposite sidesof said bolt and the extended end of said piston rod and pivotallyattached to each with their rounded sides extended away from the side ofthe block, a lever extending from said rocker plates, said lever havinga bifurcated end straddling said rocker plates, a pin engaged throughsaid bifurcated end and said plates concentric with the rounded sides ofsaid rocker plates, and means releasably retaining said lever in aninoperative position along the side of the hollow cylinder or in anoperative position extended laterally from the block.

FRED M. SIEDENBURG.

REFERENCES CITED The following references are of record inthe file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,745,024 Malone Jan. 28, 19301,811,556 Nilson June 23, 1931 1,855,508 Berck Apr. 26, 1932 1,990,004Shannon Feb. 5, 1935 2,010,679 Rosenberry et al. Aug. 6, 1935 2,072,088Dysart Mar. 2, 1937 2,170,029 Liddell et al. Aug. 22, 1939 2,351,145Pearson June 13, 1944 2,352,390 Kirkland June 2'7, 1944

